_:b56912900 <http://www.w3.org/ns/oa#hasSelector> _:b56912901 . _:b56912901 <http://www.w3.org/ns/oa#exact> "frequency" . _:b56912901 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/ns/oa#TextQuoteSelector> . _:b56912900 <http://www.w3.org/ns/oa#hasSource> <http://ns.inria.fr/covid19/arg/6137baa6da1c34a8cf59be36b52928a1930ef1f0/3> .